1. Field of the Invention
The present invention relates to an improved seat structure for use in a vehicle.
2. Description of the Related Art
Various seat structures for vehicles (hereinafter "vehicle seat structures") are known from, for example, Japanese Utility Model Publication No. HEI-1-9706 and Japanese Utility Model Laid-open Publication No. HEI-7-8060.
FIG. 8 is a schematic plan view of the vehicle seat structure disclosed in the above-mentioned No. HEI-1-9706 publication, and this seat structure 100 includes front and rear seat rows 101 and 102. The front seat row 101 consists of a pair of right and left seats 111 and 112 separated from each other transversely to the travelling direction (leftward in the figure) of the vehicle, and a front center seat 113 movable in the vehicle travelling direction between the right and left seats 111 and 112. Similarly, the rear seat row 102 consists of a pair of right and left seats 121 and 122 separated from each other transversely to the vehicle travelling direction, and a rear center seat 123 movable in the vehicle travelling direction between the right and left seats 121 and 122. Reference numeral 131 denotes a pair of parallel rails constituting a predetermined linear path along which the front and rear center seats 113 and 123 are moved in the vehicle travelling direction. Further, reference numeral L1 denotes a distance between the front and rear seat rows 101 and 102, and L2 denotes a length of the front center seat 113 in the front-rear direction of the vehicle.
With the vehicle seat structure disclosed in the HEI-1-9706 publication, a person cannot freely move or walk across the region between the front and rear seat rows 101 and 102 (that is, a so-called "walk-through" is difficult) unless the distance L1 therebetween is set to be greater than the length L2 of the front center seat 113. To permit an easy "walk-through" in the region between the front and rear seat rows 101 and 102, the vehicle seat structure disclosed in the No. HEI-1-9706 publication is designed in such a manner that the distance L1 between the front and rear row seats 101 and 102 is sufficiently greater than the length L2 of the front center seat 113.
However, the disclosed vehicle seat structure presents a very poor space efficiency because the front and rear center seats 113 and 123 of relatively large size are disposed in a limited space within the vehicle while making it necessary to provide the sufficient distance L1. The sufficient distance L1 would inevitably lead to an increased overall length of the vehicle.
The vehicle seat structure disclosed in the No. HEI-7-8060 laid-open publication includes first, second and third seat rows and the third seat row consists of right, left and center seats. Here, the center seat in the third seat row is slidable to between right and left seats of the second seat row to permit a walk-through. In this case, when the center seat is used in conjunction with one of the second and third seat rows, an empty opening or gap is formed between right and left seats in the other of the second and third seat rows. This empty opening would cause various inconveniences; for example, some object would fall into this opening. That is, when the second or third seat row is used as seats for two persons, this seat row would considerably impair the convenience and dwelling comfort of the vehicle due to lack of the center seat that may function as an armrest or table.